ML20043G704

Requests Amend to Tech Specs Adding Watchdog Timer Scram & Associated Operability & Surveillance Requirements. Computerized Control Sys Cannot Be Installed Under 10CFR50.59

ML20043G704
Person / Time
Site:	General Atomics
Issue date:	06/12/1990
From:	Weiss S Office of Nuclear Reactor Regulation
To:	Asmussen K GENERAL ATOMICS (FORMERLY GA TECHNOLOGIES, INC./GENER
References
NUDOCS 9006210032
Download: ML20043G704 (4)

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UNITED STATES -

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NUCLEAR REGULATORY COMMISSION' l

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W ASHINGTON, D. C. 20555,

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b June 12,.1990

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) Docket No. 50-89 a

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Dr. Keith A. Asmussen, Manager s

Licensing,< Safety and Nuclear Compliance General Atomics B

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. San Diego, California 92138-5608-e

Dear Dr. Asmussen:

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SUBJECT:

REVIEW 0F COMPUTERIZED CONTROL SYSTEM We have completed our review of your safety analysis prepared pursuant to.

-10CFR50.59.thatsupportsthe-installationofaGeneral-Atomics (GA) i

computerized contro1' system on the General Atomics Mark I TRIGA'Research t

Reactor.. The-safety analysis was submitted by letter dated December 9,1988.

p The: staff has reviewed the safety analysis and has-determined that_ installation B

of'the computerized control system requires an amendment to the Technical D

. Specifications' to add-the watchdog timer scram and associated operability and -

surveillance requirements, and to clarify the Technical Specification minimum p

required reactor < safety scrams to limit the powerileveliindependent channels to E

ino more than_one' digital scram. channel. The staff also determined that an

'unreviewed safety question existed'because of potential vulnerabilities or susceptibilities of the new control console in the areas of single failure, environmental and seismic qualification, surge withstand capability, electromag-

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netic: interference,-. failure modes ~ cnd effects, safety. system reliability, error t

!L' detection, ; independence, and sof tware failure which might compromise its _ ability l ;'

to.present accurate information to the operator and to provide scram signals Lwhen: required. Therefore, the computerized control system cannot be installed under 10 CFR 50.59.

3 Please. submit pursuant to 10 CFR 50.59(c)'and 50.90 within 30 days of this letter ~an amendment to your Technical Specifications along with a safety analysis ;that supports the changes.

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Thr.' Keith A. Asmussen.

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c The reporting. and/or re'cordkeeping requirements contained'in. this -letter affect fewer than ten respondents; therefore. 0MB clearance is not required under P.L.96-511'.

If Eyou have any questiuns concerning this matter, please contact Alexander 1

Adan.s, Jr., at 492-1127..

Sincerely, I

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r Seynour H. Weiss, Director.

Non-Power Reactor, Decomniissioning and i

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Environmental Project Directorate Division of Reactor Projects - III,.

l IV, V and Special Projects Office of Nuclear Reactor Regulation l

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' General Atomics Docket Nos. 50-89/163 -

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CC:-

i California Department'of Health

' ATTN:. Chief, Environmental Radiation-Control Unit Radiologic Health Section

-714 P. Street,-Room 498 Sacramento, California 95814

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Dr.-Keith A.'A.smussenL

.2-The reporting and/or recordkeeping requirements contained in this letter affect fewer than ten respondents;-therefore, OMB clearance is not required under.

~ P.L.s96-511.-.

If you'have"any questions concerning this matter, please contact Alexander

Adams, 'Jr., at.492-1127.

t Sincerely, Original signed by:

Seymour H. Weiss, Director Non-Power Reactor,- Deconnissioning? and:

Environmental Project Directorate Division of Reactor' Projects =- 111,.

IV, V.and Special_ Projects-Office of Nuclear Reactor Regulation x-cc: See next~page.

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